


A/B/O Genetics: Some Possibilities

by Acemindbreaker



Series: Omegaverse Meta [3]
Category: omegaverse - Fandom
Genre: Alpha/Beta/Omega Dynamics, Genetics, Meta, Other, Sex determination
Language: English
Status: In-Progress
Published: 2020-09-09
Updated: 2020-09-09
Packaged: 2021-03-06 21:13:36
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 6
Words: 1,768
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26375530
Author URL: https://archiveofourown.org/users/Acemindbreaker/pseuds/Acemindbreaker
Summary: Some ideas for A/B/O genetics besides the three-allele system suggested by others.
Series: Omegaverse Meta [3]
Series URL: https://archiveofourown.org/series/1459828
Kudos: 7
Collections: Omegaverse Genetics and Related Meta





	1. Chapter 1

I thought of a couple more options for how A/B/O presentation could be genetically determined. But first, I'd like to discuss the question of alleles vs sex chromosomes.

Male vs female, in real-life mammals, is determined by whole chromosomes, not single genes. However, since the Y chromosome (usually) doesn't participate in chromosomal crossover, the bundle of genes that make up the Sex-determining Region on Y (SRY) generally are inherited together. The only exceptions are the few people with Y-chromosome translocations, where part of the Y chromosome has ended up on another chromosome, which is a potential cause of intersex conditions.

A lot of sex determination is hormonally regulated. The SRY codes for the production of androgens, which set off a cascade of developmental switches that send the embryo down the AMAB developmental path. The absence of androgens means these switches don't get turned, the initial precursers to seminal structures wither away, and development proceeds along the default AFAB path instead.

Given the complexity of the differences between Alphas, Omegas and Betas, something similar likely occurs in their development. There's likely a whole bunch of genes that control the production of and response to hormones and the development of structures such as wombs, knots, anovaginal canals, or whatever else A/O individuals can have in that verse.

However, it is possible to have one or two key genes acting as switches, with everyone having the genetics to be either Alpha, Omega or Beta, but one or two genes determining which path the individual goes on.


	2. Two-Locus System

**Summary for the Chapter:**

> An A/B/O sex determination system inspired by Labrador coat color genetics.

The Labrador dog breed has three officially recognized coat colors - yellow, black and chocolate. Which coat color an individual Labrador has is determined by two genes - one gene determines whether pigment is deposited into fur (non-yellow) or not (yellow), and the other gene determines what kind of pigment the Labrador produces (black vs chocolate). If the alleles in the yellow/non-yellow locus code for yellow, it masks the effect of the other locus on coat coloration - although that locus still determines nose color:

It occurred to me that a similar system could work for A/B/O determination. Specifically, one locus determines whether or not the individual is a Beta, and if they're not a Beta, the other locus determines if they're Alpha or Omega. These could be whole chromosomes or gene switches.

I'm going to refer to the Beta/non-Beta options as B or E, and the Alpha or Omega options as A or O. So, there's four different options, depending on whether B or E is dominant and whether A or O is dominant.

Incidentally, if you like [dkwilliams](https://archiveofourown.org/works/766040/chapters/1468530)' idea of some Betas having more Alpha-like or Omega-like traits, this system could easily allow for that. Just like the variation in yellow Labradors' nose color, certain traits might leak through the Beta presentation based on what genes they have on their A/O locus. Especially if you have B dominant, you could have BE Betas have more A/O features than BB Betas. Or, if B is recessive, EB Alphas and Omegas might be a bit more Beta-like, with their A/O features slightly muted.

So, let's take a look at the options and what they bring us:


	3. If E is dominant over B, and A is dominant over O:

Alphas can have the following genotypes: EEAA, EEAO, EBAA or EBAO

Omegas can have the following: EEOO or EBOO

And Betas can have the following: BBAA, BBAO or BBOO

So, what happens with the pairings?

Alpha/Alpha (assuming Alpha females can get pregnant)

EEAA/EEAA - 100% Alphas

EEAA/EEAO - 100% Alphas

EEAA/EBAA - 100% Alphas

EEAA/EBAO - 100% Alphas

EEAO/EEAO - 75% Alphas, 25% Omegas

EEAO/EBAA - 100% Alphas

EEAO/EBAO - 75% Alphas, 25% Omegas

EBAA/EBAA - 75% Alphas, 25% Betas

EBAA/EBAO - 75% Alphas, 25% Betas

EBAO/EBAO - 56.25% Alphas, 25% Betas, 18.75% Omegas

Alpha/Omega

EEAA/EEOO - 100% Alphas

EEAA/EBOO - 100% Alphas

EEAO/EEOO - 50% Alphas, 50% Omegas

EEAO/EBOO - 50% Alphas, 50% Omegas

EBAA/EEOO - 100% Alphas

EBAA/EBOO - 50% Alphas, 50% Betas

EBAO/EEOO - 50% Alphas, 50% Omegas

EBAO/EBOO - 37.5% Alphas, 37.5% Omegas, 25% Betas

Alpha/Beta

EEAA/BBAA - 100% Alphas

EEAA/BBAO - 100% Alphas

EEAA/BBOO - 100% Alphas

EEAO/BBAA - 100% Alphas

EEAO/BBAO - 75% Alphas, 25% Omegas

EEAO/BBOO - 50% Alphas, 50% Omegas

EBAA/BBAA - 50% Alphas, 50% Betas

EBAA/BBAO - 50% Alphas, 50% Betas

EBAA/BBOO - 50% Alphas, 50% Betas

EBAO/BBAA - 50% Alphas, 50% Betas

EBAO/BBAO - 50% Betas, 37.5% Alphas, 12.5% Omegas

Beta/Beta - 100% Betas

Beta/Omega

BBAA/EEOO - 100% Alphas

BBAA/EBOO - 50% Alphas, 50% Betas

BBAO/EEOO - 50% Alphas, 50% Omegas

BBAO/EBOO - 50% Betas, 25% Alphas, 25% Omegas

Omega/Omega (assuming Omega males can impregnate others)

EEOO/EEOO - 100% Omegas

EEOO/EBOO - 100% Omegas

EBOO/EBOO - 75% Omegas, 25% Betas

Some other Omegaverse genetics metas have assumed that inheritance patterns determine how common/rare certain presentations are, but that's assuming that all alleles are equal frequency, which is unlikely to be true. You can have pretty much any prevalence you want with any inheritance pattern by tweaking allele frequency.

However, what this does determine is what outcomes are possible with specific pairings. Specifically, if E is dominant over B and A is dominant over O, then two Omegas can never have an Alpha child, and two Betas can never have anything other than Betas.


	4. If B is dominant over E, and A is dominant over O

Alphas can have the following genotypes: EEAA or EEAO

Omegas can have the following: EEOO

And Betas can have the following: BBAA, BBAO, BBOO, EBAA, EBAO or EBOO

Alpha/Alpha:

EEAA/EEAA - 100% Alphas

EEAA/EEAO - 100% Alphas

EEAO/EEAO - 75% Alphas, 25% Omegas

Alpha/Omega:

EEAA/EEOO - 100% Alpha

EEAO/EEOO - 50% Alpha, 50% Omega

Alpha/Beta:

EEAA/BBAA - 100% Betas

EEAA/BBAO - 100% Betas

EEAA/BBOO - 100% Betas

EEAA/EBAA - 50% Alphas, 50% Betas

EEAA/EBAO - 50% Alphas, 50% Betas

EEAA/EBOO - 50% Alphas, 50% Betas

EEAO/BBAA - 100% Betas

EEAO/BBAO - 100% Betas

EEAO/BBOO - 100% Betas

EEAO/EBAA - 50% Alphas, 50% Betas

EEAO/EBAO - 50% Betas, 37.5% Alphas, 12.5% Omegas

EEAO/EBOO - 50% Betas, 25% Alphas, 25% Omegas

Beta/Beta:

BBAA/BBAA - 100% Betas

BBAA/BBAO - 100% Betas

BBAA/BBOO - 100% Betas

BBAA/EBAA - 100% Betas

BBAA/EBAO - 100% Betas

BBAA/EBOO - 100% Betas

BBAO/BBAA - 100% Betas

BBAO/BBAO - 100% Betas

BBAO/BBOO - 100% Betas

BBAO/EBAA - 100% Betas

BBAO/EBAO - 100% Betas

BBAO/EBOO - 100% Betas

BBOO/BBAA - 100% Betas

BBOO/BBAO - 100% Betas

BBOO/BBOO - 100% Betas

BBOO/EBAA - 100% Betas

BBOO/EBAO - 100% Betas

BBOO/EBOO - 100% Betas

EBAA/EBAA - 75% Betas, 25% Alphas

EBAA/EBAO - 75% Betas, 25% Alphas

EBAA/EBOO - 75% Betas, 25% Alphas

EBAO/EBAO - 75% Betas, 18.75% Alphas, 6.25% Omegas

EBAO/EBOO - 75% Betas, 12.5% Alphas, 12.5% Omegas

EBOO/EBOO - 75% Betas, 25% Omegas

Beta/Omega:

BBAA/EEOO - 100% Betas

BBAO/EEOO - 100% Betas

BBOO/EEOO - 100% Betas

EBAA/EEOO - 50% Betas, 50% Alphas

EBAO/EEOO - 50% Betas, 25% Alphas, 25% Omegas

EBOO/EEOO - 50% Betas, 50% Omegas

Omega/Omega - 100% Omega

Outcomes that are impossible under this system include Betas with non-Beta parents and two Omegas having anything other than an Omega.


	5. If E is dominant over B, and O is dominant over A

Alphas can have the following genotypes: EEAA or EBAA

Omegas can have the following: EEOO, EEAO, EBOO or EBAO

And Betas can have the following: BBAA, BBAO, or BBOO

Alpha/Alpha:

EEAA/EEAA - 100% Alphas

EEAA/EBAA - 100% Alphas

EBAA/EBAA - 75% Alphas, 25% Betas

Alpha/Omega:

EEAA/EEOO - 100% Omegas

EEAA/EEAO - 50% Alphas, 50% Omegas

EEAA/EBOO - 100% Omegas

EEAA/EBAO - 50% Alphas, 50% Omegas

EBAA/EEOO - 100% Omegas

EBAA/EEAO - 50% Alphas, 50% Omegas

EBAA/EBOO - 75% Omegas, 25% Betas

EBAA/EBAO - 37.5% Alphas, 37.5% Omegas, 25% Betas

Alpha/Beta:

EEAA/BBAA - 100% Alphas

EEAA/BBAO - 50% Alphas, 50% Omegas

EEAA/BBOO - 100% Omegas

EBAA/BBAA - 50% Alphas, 50% Betas

EBAA/BBAO - 50% Betas, 25% Alphas, 25% Omegas

EBAA/BBOO - 50% Betas, 50% Omegas

Beta/Beta - 100% Betas

Beta/Omega:

BBAA/EEOO - 100% Omegas

BBAA/EEAO - 50% Alphas, 50% Omegas

BBAA/EBOO - 50% Betas, 50% Omegas

BBAA/EBAO - 50% Betas, 25% Alphas, 25% Omegas

BBAO/EEOO - 100% Omegas

BBAO/EEAO - 75% Omegas, 25% Alphas

BBAO/EBOO - 50% Betas, 50% Omegas

BBAO/EBAO - 50% Betas, 37.5% Omegas, 12.5% Alphas

BBOO/EEOO - 100% Omegas

BBOO/EEAO - 100% Omegas

BBOO/EBOO - 50% Betas, 50% Omegas

BBOO/EBAO - 50% Betas, 50% Omegas

Omega/Omega

EEOO/EEOO - 100% Omegas

EEOO/EEAO - 100% Omegas

EEOO/EBOO - 100% Omegas

EEOO/EBAO - 100% Omegas

EEAO/EEAO - 75% Omegas, 25% Alphas

EEAO/EBOO - 100% Omegas

EEAO/EBAO - 75% Omegas, 25% Alphas

EBOO/EBOO - 75% Omegas, 25% Betas

EBOO/EBAO - 75% Omegas, 25% Betas

EBAO/EBAO - 56.25% Omegas, 25% Betas, 18.75% Alphas

Beta/Beta pairings can only have Beta offspring, and Alpha/Alpha pairings can't have Omega offspring.


	6. Chapter 6

If B is dominant over E, and O is dominant over A, then:

Alphas can have the following genotypes:  EEAA

Omegas can have the following:  EEOO or  EEAO

And Betas can have the following:  BBAA,  BBAO,  BBOO,  EBAA,  EBAO or  EBOO

Alpha/Alpha - 100% Alphas

Alpha/Omega:

EEAA/EEOO - 100% Omegas

EEAA/EEAO - 50% Alphas, 50% Omegas

Alpha/Beta:

EEAA/BBAA - 100% Betas

EEAA/BBAO - 100% Betas

EEAA/BBOO - 100% Betas

EEAA/EBAA - 50% Alphas, 50% Betas

EEAA/EBAO - 50% Betas, 25% Alphas, 25% Omegas

EEAA/EBOO - 50% Betas, 50% Omegas

Beta/Beta:

BBAA/BBAA - 100% Betas

BBAA/BBAO - 100% Betas

BBAA/BBOO - 100% Betas

BBAA/EBAA - 100% Betas

BBAA/EBAO - 100% Betas

BBAA/EBOO - 100% Betas

BBAO/BBAO - 100% Betas

BBAO/BBOO - 100% Betas

BBAO/EBAA - 100% Betas

BBAO/EBAO - 100% Betas

BBAO/EBOO - 100% Betas

BBOO/BBOO - 100% Betas

BBOO/EBAA - 100% Betas

BBOO/EBAO - 100% Betas

BBOO/EBOO - 100% Betas

EBAA/EBAA - 75% Betas, 25% Alphas

EBAA/EBAO - 75% Betas, 12.5% Alphas, 12.5% Omegas

EBAA/EBOO - 75% Betas, 25% Omegas

EBAO/EBAO - 75% Betas, 18.75% Omegas, 6.25% Alphas

EBAO/EBOO - 75% Betas, 25% Omegas

EBOO/EBOO - 75% Betas, 25% Omegas

Beta/Omega:

BBAA/EEOO - 100% Betas

BBAA/EEAO - 100% Betas

BBAO/EEOO - 100% Betas

BBAO/EEAO - 100% Betas

BBOO/EEOO - 100% Betas

BBOO/EEAO - 100% Betas

EBAA/EEOO - 50% Betas, 50% Omegas

EBAA/EEAO - 50% Betas, 25% Alphas, 25% Omegas

EBAO/EEOO - 50% Betas, 50% Omegas

EBAO/EEAO - 50% Betas, 37.5% Omegas, 12.5% Alphas

EBOO/EEOO - 50% Betas, 50% Omegas

EBOO/EEAO - 50% Betas, 50% Omegas

Omega/Omega

EEOO/EEOO - 100% Omegas

EEOO/EEAO - 100% Omegas

EEAO/EEAO - 75% Omegas, 25% Alphas

Options that can't happen include Betas from two non-Beta parents or anything but Alphas from two Alpha parents.


End file.
